Agent Theodore Cacioppi testified Monday that he was watching television at home on Dec. 10, 2008 when his supervisor contacted him. The supervisor told him that the FBI had developed information that Madoff might be running the biggest Ponzi scheme in history.

Cacioppi told the jury that he had never heard of Bernie Madoff until that day, but soon learned he was a very big deal.

Cacioppi said he interviewed Madoff for about an hour before arresting him. Over the next week, the agent said he spoke to Madoff’s sons and put the 17th floor of the Lipstick Building in Midtown under quarantine.

The agent said that was so authorities could change the locks, install cameras and haul out the evidence.